Tungsten-filled polymers, such as nylons, urethanes and thermoplastic elastomers. Tungsten loadings range from 65% to 80% by weight to meet radiopacity requirements. Tungsten-filled polymers shields against radiation but far more safely than lead. Tungsten-filled polymers has the same density as lead, meaning it can shield radiation at the same level as lead. Manufacturing with lead is currently banned in Europe, and is on track to be banned in the U.S. Use of tungsten in plastics dates back several years when efforts accelerated to replace lead for radiation-shielding applications.

  Tungsten Alloy Manufacturer & Supplier: Chinatungsten Online- http://www.tungsten-alloy.com
  Tel.: 86 592 5129696; Fax: 86 592 5129797
  Email:  sales@chinatungsten.com
  Tungsten & Molybdenum Information Bank: http://i.chinatungsten.com
  Tungsten News & Tungsten Prices, 3G Version: http://3g.chinatungsten.com
  Molybdenum News & Molybdenum Price: http://news.molybdenum.com.cn

e) Oxidation of imines

The oxidation of N-alkyl imines with 30% hydrogen peroxide, in the presence of sodium tungstate dihydrate, led to the highly selective synthesis of oxaziridines in acetonitrile under mild conditions.


 

Tungsten Powder Manufacturer & Supplier: Chinatungsten Online - www.tungsten-powder.com
Tel.: 86 592 5129696; Fax: 86 592 5129797
Email: sales@chinatungsten.com
Tungsten & Molybdenum Information Bank: http://i.chinatungsten.com
Tungsten News & Tungsten Prices, 3G Version: http://3g.chinatungsten.com
Molybdenum News & Molybdenum Price: http://news.molybdenum.com.cn

Tungsten dichloro dioxide (WO2Cl2) alias is pizza grass and the system number is: CAS number: 13520-76-8, MDL number: MFCD00054136, EINECS number: 236-862-1, PubChem ID: 24863944.Synthesis of tungsten dichloro oxide as follows:
1. Preparing the reaction tube, the reaction tube has prepared a number of pure oxyhalide by chemical transmission technology.
2. Insert the tungsten oxide9.274g and tungsten chloride 7.931g in a long 15cm, 24cm diameter rigid tube, which was mixed.
3. Adding a slight excess of 1mg of WCI6 in a glass tube.
4. Connect one end of the glass tube is placed frozen in liquid nitrogen and the other end connected to a vacuum system to react together.
5. About 20h after completion of the reaction with a yellow sheet tungsten dichloro dioxide (Ⅵ) crystal in growth area. Then placed tube in reverse hot temperature gradient (200 ℃ / temperature) immediately which allow the more volatile impurities (such as WCl6 and WOCl4) condensed into the empty end of the reaction tube.

Tungsten Manufacturer & Supplier: Chinatungsten Online -http://www.tungsten-powder.com
Tel.: 86 592 5129696; Fax: 86 592 5129797
Email: sales@chinatungsten.com
Tungsten & Molybdenum Information Bank: http://i.chinatungsten.com
Tungsten News & Tungsten Prices, 3G Version: http://3g.chinatungsten.com
Molybdenum News & Molybdenum Price: http://news.molybdenum.com.cn

 

Tungsten dichloro dioxide is a chemical product of the formula WO2Cl2. The physical properties of tungsten dichloro oxide as follows: molecular weight is 286.7448, the melting point is 266 ℃, morphology is a thin sheet of yellow crystals and solubility: soluble in water, ammonia and alkali, insoluble in ethanol.

Tungsten dichloro dioxide is stable at room temperature and atmospheric pressure, but to avoid the wet oxide or an alkali metal. Storage methods are: room sealed, in a cool, airy stored under dry inert gas. WO2Cl2 is very sensitive to atmosphere’s moisture oxide and therefore the reaction tube must be opened in dry nitrogen atmosphere and stored in a vacuum or dry inert gas. WO2Cl2 has acutely toxic, must be equipped with safety measures in the case of operations, to avoid direct contact, or will cause any harm. What’s more it is also pollute water, so do not making undiluted product or large WO2Cl2’s product to reach ground water, water course or sewage system, without the relevant units allow material shall not be released to the environment.

Tungsten Manufacturer & Supplier: Chinatungsten Online -http://www.tungsten-powder.com
Tel.: 86 592 5129696; Fax: 86 592 5129797
Email: sales@chinatungsten.com
Tungsten & Molybdenum Information Bank: http://i.chinatungsten.com
Tungsten News & Tungsten Prices, 3G Version: http://3g.chinatungsten.com
Molybdenum News & Molybdenum Price: http://news.molybdenum.com.cn

 

According to Varlamov and co-workers, the synthesis of cyclic nitrones (4) can be carried out using H2O2 and a catalytic amount of sodium tungstate dihydrate, at room temperature, with moderate to high yields, as exemplified for 2-benzazepines (3).


 

Tungsten Powder Manufacturer & Supplier: Chinatungsten Online - www.tungsten-powder.com
Tel.: 86 592 5129696; Fax: 86 592 5129797
Email: sales@chinatungsten.com
Tungsten & Molybdenum Information Bank: http://i.chinatungsten.com
Tungsten News & Tungsten Prices, 3G Version: http://3g.chinatungsten.com
Molybdenum News & Molybdenum Price: http://news.molybdenum.com.cn

Reference standard of tungsten points in interrupter as follows:

On chemical analysis of tungsten in 1984------ GB / T 4324.1-4324.30

About hardness test------ Metallic Rockwell hardness test method in 1991------ GB / T 230

                                     ------ Metallic Vickers hardness test method in 1984------ GB / T 4340

Interrupter in Magneto test method in 1999------ JB / T 9864.2

Technical condition of tungsten rod in interrupter points according to provisions of JB / T 9860.2 in 1999.

Test methods of rod crystals size of tungsten, sintered tungsten bar, molybdenum and alloys refer to GB / T 4197 regulations in 1984.

Batch inspection sampling procedures and sample forms in 1987 (go for continuous checks of batch products) ------ GB / T 2828

 

Tungsten Metals Manufacturer & Supplier: Chinatungsten Online - http://www.tungsten.com.cn
 Tel.: 86 592 5129696; Fax: 86 592 5129797
 Email: sales@chinatungsten.com
 Tungsten & Molybdenum Information Bank: http://i.chinatungsten.com
 Tungsten News & Tungsten Prices, 3G Version: http://3g.chinatungsten.com
 Molybdenum News & Molybdenum Price: http://news.molybdenum.com.cn

The sodium tungstate dihydrate catalyzed oxidation of secondary amines with hydrogen peroxide gives the corresponding nitrones in methanol or water, at room temperature. Acyclic and cyclic nitrones can be obtained from secondary amines in a single step in good to excellent yields.


 

Tungsten Powder Manufacturer & Supplier: Chinatungsten Online - www.tungsten-powder.com
Tel.: 86 592 5129696; Fax: 86 592 5129797
Email: sales@chinatungsten.com
Tungsten & Molybdenum Information Bank: http://i.chinatungsten.com
Tungsten News & Tungsten Prices, 3G Version: http://3g.chinatungsten.com
Molybdenum News & Molybdenum Price: http://news.molybdenum.com.cn

The following is working principle of tungsten points in automotive relay:
Automotive relay is considered as being composed of main circuit and the control circuit. Tungsten points work in main circuit and the coil working in control circuit. In the control circuit of relay, only tungsten points can control its on-off, because of the small capacity of tungsten points, working current is low and it can’t be used to control the load with larger power consumption directly.

Applying a certain current/voltage at both ends of electromagnetic relay’s coil, and the coil will generate magnetic flux which will flow through the magnetic circuit whose compositions are core, armature, yoke and working air gap magnetic circuit.

Armature will be attracted to core’s pole face under the influence of magnetic field, therefore, normally closed tungsten points will open and normally open tungsten points will close;

When the voltage/current across the coil under a certain value, the mechanical counterforce is more than electromagnetic attraction, armature will back to its initial state; normally closed tungsten points will connect and normally open tungsten points will disconnect.


 

Tungsten Metals Manufacturer & Supplier: Chinatungsten Online - http://www.tungsten.com.cn
 Tel.: 86 592 5129696; Fax: 86 592 5129797
 Email: sales@chinatungsten.com
 Tungsten & Molybdenum Information Bank: http://i.chinatungsten.com
 Tungsten News & Tungsten Prices, 3G Version: http://3g.chinatungsten.com
 Molybdenum News & Molybdenum Price: http://news.molybdenum.com.cn

Very recently, Leonard and co-workers reported that sodium tungstate dihydrate promotes the oxidation of diamine (1) using 90% hydrogen peroxide in sulfuric acid. Since product (2) is very unstable, the authors propose that these reactions should be done with extreme caution, by knowledgeable researchers.


 

Tungsten Powder Manufacturer & Supplier: Chinatungsten Online - www.tungsten-powder.com
Tel.: 86 592 5129696; Fax: 86 592 5129797
Email: sales@chinatungsten.com
Tungsten & Molybdenum Information Bank: http://i.chinatungsten.com
Tungsten News & Tungsten Prices, 3G Version: http://3g.chinatungsten.com
Molybdenum News & Molybdenum Price: http://news.molybdenum.com.cn

According to the nature of vanadium dioxide which will cause phase change in about 68 ℃. Relevant researchers found that doping can not only reduce the phase transition temperature of vanadium dioxide, but also VO2 film can effectively reduce the VO2powder phase transition temperature. Therefore, using microwave plasma to produce tungsten vanadium dioxide films with nitrogen daped the phase transition temperature can be reduced to 35 ℃. The producing process of tungsten vanadium dioxide as follows: Using microwave plasma method to restore prepared V1.96W0.04O5 film to V0.98W0.02O2 with well controlling response parameter then doping nitrogen in V0.98W0.02O2. This method can make V1.96W0.04O5 which is stoichiometric ratio restore to different nitrogen content‘s tungsten vanadium dioxide (V0.98W0.02O2-XNY). The reaction parameter setting range is as follows: total pressure 1kPa, reactive power 100-200W, N2 flow rate of 20ml / min, H2 flow rate of 20ml/min, the reaction time is 10-30min. By setting different parameters and process conditions can produce V0.98W0.02O2 film with different amounts of nitrogen-doped. The experiment found that with the nitrogen ions incorporation can effectively reduce the phase transition temperature of tungsten vanadium dioxide film, the minimum can be reduced to 35 ℃.

Tungsten Manufacturer & Supplier: Chinatungsten Online -http://www.tungsten-powder.com
Tel.: 86 592 5129696; Fax: 86 592 5129797
Email: sales@chinatungsten.com
Tungsten & Molybdenum Information Bank: http://i.chinatungsten.com
Tungsten News & Tungsten Prices, 3G Version: http://3g.chinatungsten.com
Molybdenum News & Molybdenum Price: http://news.molybdenum.com.cn